Showing posts with label Panagiotis C. Theofanopoulos. Show all posts
Showing posts with label Panagiotis C. Theofanopoulos. Show all posts

Friday, October 5, 2018

Abstract-A Terahertz Microscopy Technique for Sweat Duct Detection


Panagiotis C. Theofanopoulos, Georgios C. Trichopoulos,

https://ieeexplore.ieee.org/document/8439158


We propose a THz imaging technique that uses high reflective index optics to improve spatial resolution and enable a novel biometrics imaging tool. Specifically, with the use of THz waves we can penetrate the drier outer skin layers and provide anatomical information on the skin's layered morphology and the underlying structures (e.g. sweat ducts). Sweat ducts are subcutaneous helical structures that exhibit absorption in the sub-THz frequency range. The proposed THz microscopy configuration can acquire high spatial resolution images of the human skin and classify sweat ducts based on the backscattered THz spectrum. In this paper, the theoretical background of the microscopy technique and the experimental design are discussed. Finally, THz images of human fingerprints are presented, verifying the imaging capabilities of the proposed configuration.

Monday, March 19, 2018

Abstract-Modeling of mmW and THz Imaging Systems Using Conjugate Field Coupling


Panagiotis C. Theofanopoulos, Georgios C. Trichopoulos

http://ieeexplore.ieee.org/document/8168378/

We propose a novel technique for efficient and robust modeling of multistatic, multidimensional, large-format millimeter-wave/terahertz imaging systems. The proposed method significantly reduces the necessary computational resources for the design of electrically large systems of multiple sensors that acquire multifrequency images, such as imaging radars used in three-dimensional mapping. To alleviate the problem, the radiated and scattered fields are individually computed for the sensor and the target, respectively, using full-wave numerical solvers. Afterward, the fields are properly combined using conjugate field coupling, thus minimizing the necessary computational resources, without compromising solution accuracy. In this letter, the theoretical background of the technique is presented, along with numerical results for beam steering and raster scanning imaging systems.